Radiant-heat superheater for boilers of the locomotive type



. Mu ch 13, 1928. 1,662,460

W. F. KEENAN, JR

RADIANT HEAT SUPERHEATER FOR BOILERS OF THE LOCOMOTIVE TYPE Filed May 19. 1924 2 Sheets-Sheet 1 Swueutoz WifiF/W 332 March 13, 1928. 1,662,460 w. F. KEENAN', JR

RADIANT HEAT SUPERHEATER FOR BOILERS OF THE LOCO'MOTIVE TYPE Filed May 19. 1924 2 Sheets-Sheet 2 Patented Mar. 13, 1928.

UNITED STATES:

WALTER FJ KEENAN; JR., 015 IPELHAIII-NEW YORK, ASSIGNOR TO TF0STER"WHEELER GOREORATION, OF-NEW YORK, N. 1 .A' GORPURATION 'OFNE'W 'YORK/ i RADIANT-HEAT'SUPERHEATER FOR BOILERS OFTHEL'OCOMOTIVETYPE;

Appl icutionifiled May 19, IBM.- fler ial-No. 714,309.

ant heat from the combustion chamber of theboiler and giving a desirably high .superheating: effect although comparatively small in ibullrand weight; and which is simple in" construct on and arrangement, and .so .d1sposed as to facilitate lnspectlon, cleanlng' andrepairs; and which will reduce the stressesand strains in the portion ofthe.

boiler structure, to-wit': the .crown sheet, which is subjected to the most severe operating conditions in locomotive boilers as now constructed.

The various features of novelty which characterizemy inventioncare pointed out Witlnparticularity inthe claims annexed to and. forminga part of this specification. For a better understanding, of the invention, however, itsadvantages, and specific objects obtained with its use, reference should be had to the accompanying drawings and descriptive matter, iii-which I have illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. 1 is asectional elevationiof a portion of aboiler-of the locomotive typey w Fig. 2 is v a section. OIlztlle line 2-2 of Fig. 1;

Figsi 3 1 and 4 are partial sections,.ea ch taken similarly to Fig.2, iand each illustrating a different modification Fig. 5 is a view taken slmilarlyto Fig, 1

illustrating a longitudinal arrangement of the. superheater elements and Fig; (i is a. section on the line 6-6 of Fig.5.

Figs. 1 and 2, A represents the shell of a :boilcr. which is .of the locomotive type, thouglrthe boiler. actually shownwin these figures was especially designed for use on a river steamboat. Brepresents the boiler firebox or combustion chamber, the roof of which is. formed by the usual crown sheet C. Fire-tubes or flues D are connected at their rear endsin thesusual mannerto the tube sheet 13" forming the front wall of, the

The 1 steam geners combustion chamber B. ated in the boiler passes through the connec surrounding. stay tubes.

drawings, andreferring first to tion A into a steam drum or chamber mounted above the boiler shell;

From. the drum E the steam passes 'throughfthe pipe E to the superheater ,in-

let hea derH Thelatter is divided in'toean. inlet compartment it andan outlet'com'part ment /1. by a transversepartition H. The steam p pe E opens to one endof the com:

partment it. From thev compartmenth the steam passes through a plurality of super? heater elements F to the "intermediate superheater header I, and-then passes. through the remainder of the superheater elements F to the outlet chambenh" inthe header H,..

from which the superheated steam passes to!- theengine. through piping (not shown) connected to. the superheated steam outlet H The superheater elements F in the construction shown iniFigs; land 2 are each in the form of anarc-shaped flattened tube of cast "w steel which extendstransversely, to the length of the boiler. andis located just beneath thecrown sheet 0 and'is curved to correspond to the contour of the latter Each element-F has connected to it :ateach end. a transversely extending tube 1G, the

tube Gr at oneend of the element being connected into the correspondlng compartment it or 72, of the header H, while thetube- G.

at theoppositeend vof the element is connected intotheheadcr I. [The tubes Gi'pass I loosely throughstay tubes K connecting the Q boiler shellito thecrown sheet C. To 'prevent chilling, .ofithesuperheater elements F and tube-connections G thereof, refractory 5 material is interposed between the crown sheetand'theupper sides. of the superheater elements, and between the tubesG and the This refractory materialhmay well be a cement such as is used in the construction of battle walls. I11

addition towpreyenting the transfer of heat from the superheater to the Water space walls. of the boiler, the refractory material.

prevents gas flow along the back of the superheater. The headcrsH and-I are se-- cured byyokes J to saddle blocks riveted to the: boiler shell. The elements 'Funite to: provideasmooth heat absorbing under surface. generally similar in contour to the under sideof the crownv sheet C, and suiliciently close tl'iereto to avoid material reduc-] tion in thegasspaoerof the firebox.

ll iththe apparatus described,it is possibleto obtain a relatively high superheating effect with a comparatively small amount of superheating surface, and with superheating means which are simple in construction, and durable, and which do not interfere with the operation of the boiler except as they do so advantageously by reducing the heat absorption by the crown sheet where the heat absorption is normally undesirably intense. The elements F may well be termed each of a single steel casting, as the length of the elements, their shape, and the manner in which they are supported permit of their contraction and expansion in response to changes in the temperatures to which they are heated, without causing objectionable deformation of the elements or without subjecting the elements or their tube connections to objectionable stresses, the tube connections being sulliciently llexible to accomi modate the bodily elongation and contraction of the elements F relative to the boiler shell and also any warping or bending of the elements F resulting from the fact that in operation their under sides are better than are their upper sides. The tubes G may be secured to the elements F and to the headers I by expanding their ends into place as tubes are commonly expanded into headers and tube sheets, and when repairs or renewals are necessary, it is a comparatively simple matter to cut the tubes G out and then replace them by new ones.

To facilitate repairs and renewals the tubes G may be vertical as shown in Fig. 3, in which case when the two tubes G connected to each element F are detached from the headers H and L, the element may be lowered into and then withdrawn from the combustion chamber B.

A superheater constructed and arranged as shown is well adapted to withstand very high temperatures, and hence in some cases it will notbe necessary to provide means for protecting the superheater against overheating during the periods in which no steam is drawn through the superheater. \Vhen it becomes necessary or desirable to flood the superheater with water, this may be accomplished by means of a pipe connection M containing a circulating pump M as shown in Fig. 3, which forces water from the boiler shell into the compartment h of the header H, and thence through the superheater elements F, header I, pipe E and drum E back into the boiler shell. M is a cut-oil ,valve in the connection M. By locating one of the superheater headers below the boiler water level as the header I is shown in Fig. 4, the superheater may be flooded by connecting the lowered superheater header to the boiler water space as by means of the valved pipe connection 0 shown in Fig. 4. In this arrangement the bodily elongation and contraction of the elements F must be accommodated mainly or entirely by the flexure of the tube G connected to the header I-I. Instead of arranging the slu'ierheater elements transversely of the longitudinal axis of the boiler they may be arranged parallel thereto as in Figs, I and 5. the superheater elements FA shown in Figs. and a are straight, while the header elements HA. and IA are curved and transverse to the boiler axis. The headers HA and IA are connected to the elements FA and to the boiler steam pipe I) in the same manner as the headers ll, and l are connected to the elements F and steam pipe E in the construction first deecribed.

While in accordance with the provisions of the statutes, 1 have illustrated and (lescribed the best 'lUl'lns of embodiment of my invention now known to me, it will be apparent to those sltilled in the art that changes may be made in the form of the apparatus tiliiClOSLtl without departing from the spirit of my invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other i'eatures.

Having now described my invention, what I claim as new and desire to secure by Lettcrs Patent, is:

1. In a boiler con'iprising an internal com bustion chamber with a crown sheet roof and lines leading away from the combustion chamber, the improvement which consists in a radiant heat sulierheater con'iprising a plurality of conduit elements arranged side by side in the combustion chaniiber immediately beneath the crown sheet.

In a boiler comprising an internal con1- bustion chamber with a crown sheet root and lines leading away from the combustion chamber, the improvement which consists in a radiant heat superheater comprising a plurality oi conduit elements arranged side by side in the combustion chamber immediately beneath the crown sheet, and heat insulating material interposed between the super heater elements and the crown sheet.

3. In a boiler comprising an internal combustion chamber and a crown sheet forn'iing the roof thereof and provided with lire tubes leading away from the combustion chamber, the improvement which consists in a radiant heat superheater composed of elements located beneath the crown sheet, tubes connected to the elements and extending to the exterior of the boiler, and stay tubes connecting the combustion chamber and boiler shell walls through which said tubes extend.

i. In a locomotive boiler con'iprising an internal combustion chamber and a crown sheet forming the roof thereof and provided with the tubes leading to the front end of the boiler from the comlmstion chamber. the improvement which consists in a radiant heat superheater COIIIPOSGCl of elements extending transversely to the length of the boiler beneath the crown sheet, tube connections to the ends of the elements extending to the exterior of the boiler, and stay tubes connecting the combustion chamber and boiler shell walls through which said tube connections extend.

5. In a boiler comprising an internal combustion chamber with a crown sheet roof and fines leading away from the combustionchamber, the improvement which consists in a radiant heat superheater comprising elements located in the combustion chamber innnediately beneath the crown sheet, and means for passing the steam to be superheated first through one group and then a second group of said elements.

6. In a locomotive boiler comprising an internal combustion chamber and a crown sheet forming the roof thereof and provided with fire tubes leading to the front end of the boiler from the combustion chamber, the improvement which consists in a radiant heat superheater composed of elements extending transversely to the length of the boiler beneath the crown sheet, and tube connections to the ends of the elements extending to the exterior of the boiler, the tube connection at one end, at least, of each superheater element, being perpendicular to the element.

Signed at New York city'in the county of New York and State of New York this 14th day of May A. D. 1924.

\VALTER FRANCIS KEENAN, JR. 

